<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .c1{
            display: inline-block;
            border-right: 15px red solid;
            border-top: 15px green solid;
            border-left: 15px blue solid;
            border-bottom: 15px yellow solid;
        }
    </style>
</head>
<body>
    <div class="c1"></div>
</body>
</html>